diff --git a/src/cljc/auto_ap/entities/invoice.cljc b/src/cljc/auto_ap/entities/invoice.cljc
index 8da143fa..e896b4e3 100644
--- a/src/cljc/auto_ap/entities/invoice.cljc
+++ b/src/cljc/auto_ap/entities/invoice.cljc
@@ -8,11 +8,11 @@
 (s/def ::invoice-number ::shared/required-identifier)
 (s/def ::date ::shared/date)
 (s/def ::total ::shared/money)
+(s/def ::vendor-id ::shared/identifier)
 
 (s/def ::invoice (s/keys :req-un [::client
                                   ::invoice-number
                                   ::date
                                   ::vendor
                                   ::total]
-                         :opt-un [
-                                  ::vendor-name]))
+                         :opt-un [::vendor-name]))